1. Field of the Invention
This invention related to a method and apparatus for storing and delivering drugs. More particular this invention relates to a method and apparatus where the drug is stored in, and delivered from, a pouch that is pressurized before delivery.
2. Discussion of the Background
Drug delivery technologies are becoming a critical part of the entire drug development process. Pharmaceutical companies are realizing the importance of drug delivery in the initial stages of drug development. The novel formulation of a drug by application of delivery technologies has opened many doors for the patients, physicians, as well as pharmaceutical companies. Moreover, drug delivery companies can offer new life to older drugs so that the drug can continue to generate more revenues for the pharmaceutical and biotechnology companies. New delivery methods also extend the product life of drugs going off patent, thus delaying the entry of generics in the market.
Drug delivery technologies are being used to not only improve pharmacokinetic and pharmacodynamic profiles, but are also being targeted to improve patient comfort and compliance. Targeted delivery of drugs is also being leveraged to reduce side effects of a number of drugs. In addition to pharmaceutical products, a number of biotechnology products are being developed that require an alternate or novel route of administration because most of them are ineffective when administered orally. An effective delivery system is thus targeted to improve the performance of both new and old drugs.
One aspect of the above said is the form of packaging and storing the drug/apparatus yet keeping a simple and convenient fashion to operate the administration procedure. In several cases the apparatus structure does not comply with the requirements for storage and transportation of the drug to the point and time of use. For example molded plastic parts are permeable to several liquid form substances and in various cases where the drug reservoir of the apparatus is made from molded plastic components the drug is introduced into the apparatus just prior to the treatment, making the administration process more sophisticated and in many cases more expensive. Other drugs are advantageously be compounded just prior to the treatment in order to extend the drug's shelf life and durability to environmental conditions between the time of manufacturing and the time of administration. This is in particularly true to biological substances such as vaccines which are advantageously kept in a powder form and reconstituting in a liquid form just prior to administration.
Pouches made of thin films or foils are advantageous for drug storage (vs. injection molded or blow molded containers) as they can be constructed from drug compatible materials with excellent barrier properties and enhanced chemical stability. In particular multilayer films and foils, co-extruded or laminated, can combine properties which provide comprehensive packaging solution including, good bonding/sealing properties, strength, chemical resistance, gas and liquids barrier, and UV and other sorts of radiation resistance.
Hypodermic injection is meant to include intra-dermal, subcutaneous and intra-muscular injections.
The invasiveness and fear of injections (resulting in poor patient compliance) as well as a financial incentive to gain valuable market share has encouraged a number of companies to develop technologies that can lead to needle-free delivery of medications. Needle-free injection devices propel a small jet of liquid or powder at high speed, causing it to penetrate the skin for subcutaneous, intradermal, or intramuscular administration. These devices have been used for mass vaccinations for a number of years; however, only recently are they being promoted as devices for the self-administration of parenteral drugs. Improvement in technology, increased development of formulations for needle-free delivery, and reduced prices are expected to spur the acceptance of and demand for needle-free devices in the coming years.
One of the forms of injectable delivery, needle-free technologies, provides an alternative to needles normally associated with injectables delivery. Needle-free injectors are devices that do not use a needle to administer medication. The mechanism involves high pressure to push the medication through the skin to the desired penetration site. Using pressure instead of the needle allows for a non-invasive method of drug delivery. Pressure is produced by using either a gas (carbon dioxide or nitrogen) or a spring device. The pressure forces the medication through a small opening in the device while it is held against the skin. This creates a fine stream of the medication that penetrates the skin. There are a few devices on the market that are spring powered, however, most are gas powered. The penetration depth of the drug is dependent upon the amount of pressure used. Devices currently on the market administer the drug to the subcutaneous, intradermal, and intramuscular tissues, together referred to as hypodermic administration.
Currently, the applications of the device are for delivering insulin, vaccines, growth hormones, and other medications. Applying the device to deliver proteins and peptides is in the initial stages of development. Some of the major companies operating in the needle-free delivery markets include Bioject, Injex (formerly Equidyne), Antares, BioValve, Crossject, PenJet, and Aradigm. Of course there are other companies, but the following is to provide readers with a brief review on some of the technologies available in needle-free devices and what makes them unique from each other.
The Biojector 2000, from BioJect has the ability to deliver both intramuscular and subcutaneous injections up to 1 ml. Vaccines and medications can be delivered using this device. It was designed to be used in professional settings, delivering multiple injections. This system has three components: injection device, disposable needle-free syringe, and a CO2 cartridge. Each CO2 cartridge can deliver between 10 and 15 injections before having to be replaced.
Vitajet 3:
The Vitajet is currently used to deliver 0.02 to 0.50 ml. The device has three components: the reusable injection device, disposable Crystal Check nozzle, and disposable vial holder. The nozzle is replaced once a week. It may be used in the home for self-administration. The Vitajet 3 is powered by an internal spring. More than 3,000 injections may be delivered from single device.
Iject:
Currently in development, the Iject has the ability to deliver medication subcutaneously, intramuscularly, and intradermally. It may be set on various injection volumes. This device is gas powered and may be available either as a pre-filled single-use disposable system or a reusable device. The reusable version uses pre-filled cartridges of medication that are replaced.
Injex 30:
The Injex 30 delivers medication to the subcutaneous tissue. Delivering from 0.05 to 0.30 ml, the Injex 30 consists of a main body, a trigger release, and a dual safety system. A safety system helps to prevent accidental discharge. The system is made of stainless steel to be durable.
Injex 50:
Injex 50 is designed for frequent use and has the ability to deliver larger dosage amounts from 0.10 to 0.50 ml per injection.
Jet Syringe:
Currently in development stages, the Jet Syringe is a single-use disposable needle-free injection device that is powered by a spring mechanism. Advantages of the device are its small design and convenience of attaching a pharmaceutical pre-filled ampule. The Jet Syringe, which can deliver up to 0.5 ml, can be configured with an adjustable dose fillable ampule or a proprietary prefilled glass ampule for fixed-dose applications. A general use 510(k) clearance has been granted for administration of subcutaneous injections. The prefilled version is also ideal for subcutaneous vaccines.
Antares Medi-Jector Vision:
Antares' Medi-Jector Vision is a small, handheld device that delivers to the subcutaneous tissue. The device is targeted for delivery of insulin for not only adults but also children, and is compatible with all brands of U-100 insulin. The Medi-Jector Vision uses pressure to create a micro-thin stream of insulin that penetrates the skin and is deposited into the subcutaneous (fatty) tissue in a fraction of a second.
Aradigm Intraject:
The Intraject is expected to enter the market in the next couple of years. Intraject is composed of two main parts: the glass capsule with a pre-filled volume of 0.5 ml, and a compact nitrogen gas power source (“the actuator”). To use Intraject, the patient snaps off the plastic tip (which acts as a sterile seal), removes the safety band, and presses the device against an area of the skin to activate delivery. The delivery process is completed in less than 60 milliseconds. Formulations delivered via Intraject are usually identical to those delivered via conventional subcutaneous injection, allowing for an abbreviated bioequivalence-based clinical and regulatory pathway. Since the drug-containing capsule is made of glass, existing stability in glass ampules can also be used to support Intraject filings.
BioValve Miniject:
Biovalve's Mini-Ject needle-free system is designed to deliver a wide range of drugs, ranging from small molecules to large proteins, fragile antibodies, and vaccines. The small, convenient, and disposable device can be targeted to deliver via intradermal, subcutaneous, or intramuscular routes. Miniject's propulsion technology includes a multi-phased energy system that can deliver from 0.1- to 1.3-ml drug volumes. Mini-Ject's orifice is manufactured using a proprietary process to ensure exit taper and orifice alignment, resulting in minimal turbulence and improved performance. The device, which is filled on a standard pharmaceutical line, can be configured to deliver solutions, for which it has a single part, solution-stable, prefilled cartridge. It is also designed for the delivery of lyophilized formulations, for which it has a dual-stage cartridge.
Crossject:
The device is a single-use pre-filled needle-free injection targeted for subcutaneous, intramuscular, or intradermal use. Based on novel gas generator technology, Crossject can deliver drug volumes from 0.2 to 1 ml in few hundreds of a second. The company, which likens the gas-generation reaction to that used in car airbags, points out that there is no pressurized gas present while the injector is kept in storage, thus avoiding the difficulties of gas leakage. The gas generator contains the chemical energy source and is triggered by the impact of a spring on the reactive materials. The drug container is composed of a glass tube (type I borosilicate) capped at both ends by elastomer corks. The third module, the nozzle, is manufactured from polycarbonate and can contain one or more orifices depending on the quantity and viscosity of the formulation. The orifices are 100 to 300 μm in diameter. CrossJect cites close control over the gas pressure profile as one of the advantages of its device over pressurized gas- and spring-propelled systems. This enables the injection profile to be optimized and the precise depth of injection to be determined.
PenJet:
The device is a small needle-less, disposable jet injector that delivers a single dose of medication using nitrogen gas canisters. PenJet can deliver both liquid and lyophilized drugs with volumes ranging from 0.1 to 0.5 ml. PenJet is powered by self-contained compressed inert gas and is either shipped prefilled with a drug or filled prior to delivering a needle-less injection. Ease of operation and low cost make PenJet applicable for usages ranging from mass inoculations of entire populations to home delivery of pharmaceuticals by patients or their caregivers. They are available for needle-less subcutaneous, intradermal, and some intramuscular injections.
Several disadvantages exist with the above mentioned devices and their technology including:
1. All of the above devices and technologies utilize a drug reservoir in a fashion of a cylinder and a piston. This construction present sealing challenges between the drug cylinder and piston as well as friction issues.
2. The activation mechanisms are either gas loaded piston or spring loaded arrangement which are complex and expensive to manufacture. It would be advantageous if the gas pressure could be applied directly to the drug reservoir avoiding redundancy of mechanisms.
3. In the spring loaded devices the loading mechanisms are cumbersome to operate. This disadvantage becomes more pronounced where massive administration has to be conducted for example in a massive vaccination campaign.
4. For those devices that comprise a prefilled reservoir, said reservoir is usually made from glass and it is expensive to manufacture.
5. Other devices utilize reservoirs comprising molded plastic walls, which are not suitable for storing and transportation of the drugs. In this case the administration procedure requires filling the device prior to use, making the procedure cumbersome and in certain devices a contamination risk.
6. Moreover all of the above devices require a potential energy storage or generation means capable of instantly pressurizing the drug reservoir. That requirement limits the choice of adequate solutions to relatively expensive ones or sophisticated to operate solutions.
7. The above prior art needle free devices require extremely high pressure (about 300 bar) to initially penetrate the skin which impose extreme mechanical requirements on the components of these devices.
8. And lastly, none of the above devices is inherently adequate for combination-drug administration, or drug reconstitution (resuscitation), where content of separately sealed reservoirs are to be expelled in a single administration, as these device simply dispense the solution that present in its piston fashion reservoirs.
The above listed disadvantages are partly addressed where the piston/cylinder fashion drug reservoir is replaced by a collapsible reservoir. In the prior art there are also known devices for a needle-free injection of liquids which avoid stoppers or the like. European patent application 0 370 571 describes a system where an ampule which contains a liquid medication is being mechanically compressed by a rod. This compression drives the liquid medication through one or more orifices to generate a liquid jet. While this apparatus mostly avoids the problems associated with frictional surfaces and stoppers moving in a cylinder this apparatus has a drawback that the flexible part of the ampule may be destroyed when pressed by the rod. A further drawback of this device is that the pressures which can be applied to the ampule are limited due to the risk of destruction and also by the relatively low energy stored in a spring. Another disadvantage of this apparatus is that a mechanical compression of the ampule by a rod cannot guarantee that the liquid within the ampule is being ejected totally. Such a device is therefore insufficient when it is desired to inject a specific amount of medication.
In FR-1.121.237 there is described a device for the hypodermic injection of liquids using a high pressurized liquid jet. The device comprises a compressible container for liquid medication which is attached to a unit having a fluid channel. The unit with the fluid channel is connected to a unit with a nozzle so that a continuous channel is being formed through which the liquid medication can be expelled. For a hypodermic injection the unit with the channel is placed on a mounting element so that the medication container is surrounded by a chamber and pressure is applied to said chamber by ignition of an explosive. The document FR-1.121.237 teaches that the medication container and the unit with the channel are combined by the user. The user fills the liquid to be injected into the medication container and tightly closes the medication container by screwing on the unit with the fluid channel. Such a process is not only cumbersome but it also bears the risk that the medication and/or the fluid channel is contaminated. The injection of a contaminated medical fluid is totally unacceptable in the therapeutic field. This problem of contamination is mostly unresolved in the prior art of hypodermic liquid injection. Furthermore the FR-1.121.237 does not give any information regarding the pressure of the liquid jet and how this pressure can be controlled to be in a specific range or how the pressure can be changed by the user to comply with his specific needs. A further drawback of the system described in FR-1.121.237 is that no means for purging air from the liquid chamber are described. However, air within the liquid chamber leads to disadvantageous effects as described further below.
Reference GB-697,643 describes a device for hypodermic injections using a flexible or collapsible element which is being compressed. The device described in this document is very complicated and uses a rechargeable pressure chamber into which a pressurized gas is introduced and in addition thereto a chamber with a hydraulic fluid is employed. With this device it is possible to control the pressure by which the liquid is being expelled from the container. However, a flexible container is needed into which the collapsible medication container is being introduced. From the function of this device it must be assumed that it is impossible to expel all of the fluid which is within the medication container. The document GB-697,643 further discloses a medication container which is sealed and can be used to store a medication under sterile conditions. However, this document does not disclose a medication container including a sterile nozzle. Therefore this document does not give an overall solution to the object of sterile injection.
U.S. Pat. Nos. 3,387,609, and 4,051,851 describe a prefilled disposable hypodermic syringe having a diaphragm, made from a resilient and penetrable material, at the dispensing end of a medicament vial, preventing the fluid connection between said medicament and the administration mean of the device. A rupturing member positioned in proximity to said diaphragm such that, upon presence of pressure in the vial said diaphragm collapse toward the rupturing member at which point the diaphragm is ruptured establishing a fluid communication between the vial and the administration means. Several other patents (referring to the above patents (including U.S. Pat. Nos. 4,0551,851; 4,072,149; 4,084,718; 6,354,603) repeat the fundamental idea of rupturing a sealed medicament reservoir in similar fashions and suffer from a common drawback, and incompetence with the device of the present invention. While U.S. Pat. Nos. 3,387,609 and 4,051,851 describes a rupturable reservoir one may understand that the rupturing is desired immediately upon performing the injection, and that excessive pressure built in the vial prior to the rupture of the diaphragm works against the purpose of the idea. Therefore the rupturing mechanism of the present invention is incompetence for controlling the drug administration pressure. It is also noted that the integrity of the prefilled package is not established and that the sealing of the medicament is limited.
The disadvantages listed above for the devices using collapsible reservoir are addressed by U.S. Pat. No. 6,258,063 which describes A hypodermic injection system allows for the generation of a high pressure liquid jet capable of passing through the skin. The system uses two regions, the first region being flexible or squeezable and the second region having at least one exiting orifice through which the liquid jet can be expelled. The flexible region can be deformed by a pressure change in the surrounding container generated by an activatable gas generator that generates pressure within the first region that causes the liquid to be expelled. The patent application describes two types of medication units—Type A and Type B—and types device construction to operate said medication units types. The Type B configuration comprises a medicament reservoir having flexible walls possibly Made from films or foils. The medicament is pressurized by exposing the reservoir wall to external pressure. Upon pressurizing the medicament a portion of the wall is displaced toward a rupturing member, thereupon the reservoir is ruptured and the medicament is expelled toward the administration means. U.S. Pat. No. 6,258,063 further describes means for controlling the pressure applied to the reservoir. Since this patent is limited pressurizing means which instantly deliver high pressure to the reservoir, provided by explosion, it does not refer to control mechanism that which prevent the rupture if the pressure in the reservoir has not reached a defined threshold. On the contrary, U.S. Pat. No. 6,258,063 refers to situation where it is needed to get rid of excess pressure due to the excessively high pressure that the explosion can generate. Thus the pressure control in U.S. Pat. No. 6,258,063 is limited to control of exhaust of the combustion products.
U.S. Pat. No. 6,258,063 also describes means of sealing the ruptured area around a fluid conduit such that the medicament is directed to the fluid conduit leading to the administration device. The sealing is achieved by venting the area around the ruptured portion which causes the walls around the ruptured area to press against the walls around the fluid conduit due to the high pressure of the medicament, forming a surface to surface seal between the wall of the reservoir and the wall around the rupturing member.
The apparatus related to as Type B in U.S. Pat. No. 6,258,063 seem very similar to the present invention but has some technical drawbacks which are overcome by the present invention. In U.S. Pat. No. 6,258,063 the reservoir is ruptured by the rupturing member prior to establishing the sealing of the reservoir wall around the rupturing member. It is supposed that the inventors have assumed a very reliable sealing between the rupturing member and the reservoir wall prior to establishing the sealing between the reservoir wall and the walls around the rupturing member otherwise some of the medicament is due to leak out in the transition time. But this assumption in unlikely to hold when the sealing is to happen between a very thin needle and a thin wall in particular with a Polypropylene wall which is relatively rigid material. Disadvantageously, such leakage would not only affect the accuracy of the administered dose but would also expel the leaked medicament to the surrounding, potentially exposing other people to the medicament. It is also likely that the inventors of U.S. Pat. No. 6,258,063 has assumed that the transition time between the rupturing of the reservoir wall, and the time that said wall form a tight seal with the wall around the rupturing member to be very short and so in the worst case an insignificant amount of medicament will be expelled. While this assumption may be acceptable for certain indications it may be poor for others where highly accurate dose is required or where expelling the leaked drug to the environment is not acceptable. Therefore, while the present invention adopts the rupturing configuration of the Type B apparatus of U.S. Pat. No. 6,258,063 for certain embodiments, it also proposes alternative advantageous embodiments with improved rupturing mechanism which prevent any leakage of deliverable fluid, which is essential where accurate dose administration is obligated.
A further technical limitation of the apparatus related to as Type B in U.S. Pat. No. 6,258,063 is that the medication unit which consist of two major walls is being sandwiched between a first shell and a second shell. While this construction is feasible and acceptable for some embodiments it has several disadvantages: 1) it unnecessarily complicates the manufacturing assembly as the reservoir participates in the construction of the handling device, 2) it introduce unnecessarily sealing failure modes as the reservoir wall participate in the sealing of the handling device, 3) it introduce super demands from the reservoir wall which has to comply with several functions, and 4) Fixing the reservoir walls to the handling unit can introduce excessive stresses in the wall vs. otherwise pure pressure, and 5) more constrains between components in an assembly means tougher tolerance challenges. While said construction has been adopted by the present invention for certain embodiments of the present invention, the present invention presents an advantageous construction where the reservoir is an independent unit accommodated with in the handling device and not participating in the construction of the handling unit, thus overcoming the above disadvantages. The present invention thus presents several advantages including simplifying the manufacturing assembly, reduce sealing failure modes, and reduce unwanted stress from the reservoir walls.
Also, the apparatus described in U.S. Pat. No. 6,258,063 is limited to a specific form of application where a single medicament is instantly delivered to the skin, and does not comply with any application where more than a single substance has to be stored and delivered.
Drug administration means which incorporate means for mixing or constituting drug components are known in the art. U.S. Pat. No. 7,011,650 describes multi-dose syringe, and US patent application 20040249339 describes an injection device that to inject sequentially two fluids into a patient. Both of these patents describe complex constructions utilizing a piston and a barrel which will be expensive to manufacture. The reservoirs in these patents comprise rigid wall portion and rubber sealing members which are mostly unsuitable for long term storage of pharmaceutical compounds from the time of manufacturing to the time of administration.
Also, the present invention proposes means for lowering the pressure requirements for penetrating the skin there for lowering the pressure withstand demand from the apparatus.
All of the above needle-free injectors are hand held devices for administration by a care giver or self-administration. For various reasons it is advantageous to have a needle free device in a fashion of a patch. One reason is the fear factor. One of the advantages of needless injectors over regular syringes is the increased compliance due to the avoidance of needles which cause resistance by many patients. Yet, needleless injection is painful and so fear resistance may still exist by many patients which my cause the patient to move during administration. Such movement can affect the efficiency of the administered dose penetration, and in the worse case can injure the patient. The jet of a needless injector is capable of cutting the skin if it points in the wrong angle to the skin. It is therefore advantageous to device the procedure to two stages into a) attaching a patch device to the skin, b) activate the device, c) injection is performed after a short delay, and d) remove the patch. For self administration it will be an easier procedure to first locate the device on the target place on the body and then activate the device, rather than doing the two functions at the same time. It is therefore the object of the invention to provide a patch fashion needleless injector.
Hypodermic drug delivery devices which comprise internal deliverable fluid reservoir, an administration needle, and insertion mechanism for inserting the needle are well known in the art. Particularly interesting are those devices in which said administration needle is disconnected from said reservoir until the time of activation at which point the devices manipulates the reservoir and the administration device to establish fluid communication. Despite the fact that the drug reservoir in said devices is confined in the device it is completely sealed and merely provide a packaging means, eliminating exposure and therefore influence of further elements in the device on the deliverable fluid, as well as reducing leakage risks. U.S. Pat. No. 6,979,316 presents an auto-injector for rapid delivery of a bolus. The patent teaches a mechanism for extending an administration needle from a first concealed position in the package to an exposed position, followed by rupturing of said reservoir by a rupturing member which establishes a fluid communication between the reservoir and said administration device. At a subsequent step the reservoir is pressurized by yet another part of said mechanism. The differentiation of parts of the mechanism to different functions of U.S. Pat. No. 6,979,316 result in a relatively complex mechanism. Also the fact that the reservoir is first ruptured followed by pressurizing the reservoir puts higher demands on the pressurizing mechanism to react fast in order to release a bolus from said reservoir. U.S. Pat. No. 5,957,895 presents yet another idea of a drug delivery device comprising a hypodermic needle and a reservoir which are disconnected until the time of activation. The pressurizing mechanism of the reservoir in the above prior art comprise separate mechanisms or sub-mechanisms for creating fluid communication between the reservoir and the administration device, and for propelling the deliverable fluid, resulting in redundancy of mechanisms which effect complexity and costs of these apparatuses. The present invention comprises a pressurizing device for propelling the deliverable fluid from the reservoir to the body of a patient, where said pressurizing device is also responsible to urge the reservoir rupture and the needle insertion therefore simplifying the apparatus and reducing manufacturing costs. It also establish an inherently logical sequence in which the deliverable fluid can not be expelled prior to the insertion of the administration device to the body of the patient.
An apparatus which apparently has many similarities with the apparatus of the present invention is featured in U.S. Pat. No. 6,656,147 (here after referred to as U.S. Pat. No. 147). U.S. Pat. No. 147 describes a device for delivering a substance into the skin of a patient includes a housing and a plurality of microneedles for penetrating the skin. The housing includes a bottom wall with a plurality of apertures for supplying the substance to the microneedles. The housing also includes a flexible top cover member enclosing a bladder containing the substance to be delivered. The bottom wall of the housing has at least one cannula facing the bladder. Pressing on the top cover member causes the cannula to puncture the bladder and deliver the substance to the microneedles for delivery to the patient. In one embodiment, the cannula is surrounded by a flexible member to prevent piercing of the bladder until sufficient pressure is applied to the cover member to depress the flexible member. Therefore U.S. Pat. No. 147 provides a pressurizing device which pressurizes a reservoir, in a form of a pre-sealed bladder, forcing the bladder against a rupturing member to rupture the bladder and to establish fluid communication between the reservoir and the administration device. Unlike the present invention U.S. Pat. No. 147 does not teach that the reservoir and the area around the rupturing member should establish a fluid tight seal, in fact U.S. Pat. No. 147 suggests the opposite where the area between the reservoir and the rupturing members is part of the fluid passage from the reservoir to the administration device. This raises a list of concerns that are not particularly addressed by U.S. Pat. No. 147 and are listed here under:
a) contamination—the space between the bladder and the base (where the rupturing members are located) is exposed to contamination from the time that the apparatus has been removed from the package to the time that the cover is closed.
b) The chamber in which the reservoir is accommodated contains air (by definition of the description in this patent) which will be exposed to the deliverable fluid after rupturing of the reservoir and most likely be delivered to the body of a patient. While it might not be desirable to administrate air to begin with, in this case the air is ambient air that was picked up prior to closing the cover, therefore bare a contamination risk, as well as unpredictable dose size. In fact if the cover establish an air tight seal with the chamber where the reservoir is accommodated (U.S. Pat. No. 147 is not clear about this point) than it is most likely that air will be delivered to the patient when the chamber is pressurized, even before the reservoir has been ruptured.
c) If the cover does not establish a fluid tight seal with the chamber then the deliverable fluid can be spilled from the apparatus and effect the dose accuracy. It is also unclear in this case what propels the deliverable fluid to the administration device as (if the cover does not establish a fluid tight seal with the chamber) the chamber is not pressurized.
The apparatus of the present invention overcomes the above disadvantages by providing a fluid tight seal between the reservoir and the area around the rupturing member.
It is unclear from U.S. Pat. No. 147 whether the cover establishes a fluid tight seal on the chamber where the reservoir is accommodated. The invention summary, as well as the descriptions and the claims do not refer to pressurizing the chamber but just to pressurizing the reservoir and therefore we argue that the apparatus of U.S. Pat. No. 147 is not practical for the purpose of administrating fluids to the body.
Unlike the present invention, U.S. Pat. No. 147 does not provide an auto-insertion mean or auto retraction means of the administration means which present a contamination and injuries risk.
U.S. Pat. No. 147 teaches a method for drug reconstitution by having a first ingredient in the reservoir and a second ingredient, in a dry form, in the fluid passage from the reservoir to the fluid exit of the administration device. Disadvantageously this second ingredient is exposed to ambient air until the cover of the apparatus has been closed. Another disadvantage is that there is no time for the ingredients to interact prior to administrating to the body. The present invention overcomes these disadvantages by storing the ingredients in sealed and separated compartments in the reservoir. The present invention provides the time necessary for the ingredients to interact prior to administration.
U.S. Pat. No. 6,780,171 (here after referred to as U.S. Pat. No. 171) features a further apparatus, generally from the authors of U.S. Pat. No. 147, that overcomes part of the disadvantages of the last by featuring a fluid tight seal communication between the reservoir and the area around the rupturing member (in the embodiment presented in U.S. Pat. No. 171 we refer to the rupturing member as the tip of a needle, and the area around the rupturing member is the inlet to the conduit from the reservoir). The invention of U.S. Pat. No. 171 does not provide means for conditioning a threshold pressure prior to rupturing the reservoir and it does not seem the intension of this invention to have a threshold pressure prior to rupturing. While this may not present a disadvantage with the administration means suggested by U.S. Pat. No. 171, it does present a disadvantage with other administration devices covered by the present invention including a needleless injector. The apparatus of the present invention provides a rupturing-control mechanism which conditions the rupture with the presence of a threshold pressure in the reservoir. U.S. Pat. No. 171 does not provide means for preventing rupture of the reservoir prior to having the administration device properly communicating with the body of the patient, and therefore accidental or premature closing of the cover will result in rupturing of the reservoir and spillage of the deliverable fluid. The apparatus of the present invention overcomes this disadvantage by providing a safety catch which prevents activation if the administration device is not properly communicating with the body of the patient.
Lastly the reservoir of U.S. Pat. No. 171 comprises a complex assembly which includes the rupturing means and the administration means and is not very convenient and safe to run in automatic filling processes, and in particularly not in standard or retrofitted filling lines such as form-fill-seal manufacturing lines. The present invention overcomes this disadvantage by providing a simple reservoir construction which is well adequate for processing and filling by standard equipment in the industry.
It is therefore the object of this invention to provide a pressurized hypodermic drug delivery apparatus where the drug can be delivered directly from a none-expensive sterile storage package.
It is a further object of the invention to provide an apparatus for administrating combination drugs.
It is a further object of the invention to provide an apparatus for reconstitution (resuscitation) drugs.
It is a further object of this invention to provide an apparatus for instantly delivering pressurized drug using a relatively slow pressure building device therefore allowing simpler and less expensive pressure building mechanisms to be utilized.
It is a further objective of the invention to reduce the parts count and in particular the moving parts and sealing members.
It is a further object of the invention to provide a simple and inexpensive safety catch.
It is a further object of the present invention to provide a hypodermic drug delivery apparatus which requires relative low pressure for penetrating the skin.
It is a further object of the invention to provide an electronic circuitry for monitoring and controlling the apparatus function.
It is further the object of the present invention to provide means for monitoring the drug conditions and history.
It is a further object of the invention to provide means for conditioning the drug prior to administration.
It is a further object of the invention to provide a reservoir that complies with the objectives of the apparatus of the present invention.
It is a further object of the invention to provide an electronic circuitry for monitoring and controlling the apparatus and the administration which is at least partially comprised in the reservoir assembly.
It is a further object of the invention to provide a needleless hypodermic injection apparatus in a patch fashion.
Those and other objectives of the invention will become clear in the description of the invention.
The invention will now be described in connection with certain preferred embodiments with reference to the following illustrative figures so that it may be more fully understood.
With specific reference now to the figures in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of the preferred embodiments of the present invention only and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the invention. In this regard, no attempt is made to show structural details of the invention in more detail than is necessary for a fundamental understanding of the invention, the description taken with the drawings making apparent to those skilled in the art how the several forms of the invention may be embodied in practice.